Researchers across the U.S. are preparing to recruit individuals diagnosed with restless legs syndrome and a history of symptoms at least 15 nights a month for participation in a major phase III drug trial. Target participants are RLS patients 18 years and older.

The trial, sponsored by GlaxoSmithKline, will evaluate the effectiveness, safety and tolerability vs. placebo of a timed release drug - GSK1838262 (XP13512) - as a means of reducing sleep disturbance associated with restless legs syndrome. Effectiveness will be measured via plysomnography study to measure change in wake time during sleep at the end of each treatment period vs. baseline.

The drug has been defined as a “novel prodrug of gabapentin” (Neurontin) – that is, a drug that is converted to gabapentin in the intestine – and, it is suggested, is more predictably absorbed and more bioavailable. In timed release form, it appears to offer decreased dosing frequency. See the recently published article “Clinical Pharmacokinetics of XP13512, a Novel Transported Prodrug of Gabapentin,” offered free of charge by the Journal of Clinical Pharmacology. Also, to read one clinician’s comments on XP13512 vs. gabapentin as a treatment for restless legs syndrome, click here.